View Full Version : HDR-FX1 Widescreen vs Frame size??


Donald Blake
December 24th, 2006, 12:16 PM
Hey everyone!

Is it just me or i'm getting a hard time every time i want to capture or render a video file frome my FX1? this i really a basic question...

What is the real frame size of a widescreen DV clip filmed by the FX1 ???

All the editing programs have 720x480 (widescreen) but when i choose them the image is horizontaly squeezed, so in each programs i have to build my own custom profile every time, either in AVI, MPG, WMV etc... right now i'm using Vegas 7 and it's the same story! It isin't written in the FX1's user manual either.

So right now with Vegas 7 i'm capturing in 720x480 but black lines are added (letter boxe) to keep the right ratio, so in fact the real format would be 720x405 if you take out those black lines.

When i render it out, i use a custom profile with 852x480 but i still have very small black lines as if the ratio was close but still not right.

I know i'm not the only one with this question, Carl Downs wrote this thread on HD (http://dvinfo.net/conf/showthread.php?t=81275)

Boyd Ostroff
December 24th, 2006, 12:32 PM
Hi Donald! All standard defintion NTSC DV is 720x480. If you're shooting in widescreen mode, then a signal is imbedded in the video which should tell your software to stretch it horizonally. So in other words, both 4:3 and 16:9 contain 720x480 pixels, but the width of each pixel is interpreted differently.

I'm on the Mac so I can't help with your software question, but you probably need to use a widescreen or anamorphic setting in your clips and sequences for them to be properly interpreted. What you describe sounds like what I would expect to happen if you dropped a 16:9 clip into a 4:3 timeline. The software would letterbox it to fit.

I'm moving your post to our Vegas forum since it's really a software and not a camera issue. I'm sure someone there will be able to help.

Richard Iredale
January 22nd, 2007, 12:58 AM
Don:

You're thinking too hard.

Also, you're assuming that a "pixel" is always square, or as wide as it is tall. In reality, with modern image processing technology a pixel can be skinny or fat.

If you are shooting NTSC DV, then your camera is sending 720x480-pixel images to your PC over the Firewire where each pixel is assumed to be a bit skinny; actually, if the pixel height is 1 then the width is 0.9091. If you do the math then you'll find that an NTSC DV image is not exactly in a 4:3 shape, but actually very slightly wider (this explains why a 4:3 still imported into a DV timeline will show very narrow black bars on each side).

If, on the other hand, you shot your video in NTSC DV Wide, then the camera still sends images comprised of 720x480 pixels, but this time the pixels are meant to be shown as fat pixels, 1.21 times as wide as they are tall. Still the same number of pixels, but fat pixels rather than thin pixels, so the overall image is wider; in fact, a 16x9 overall shape.

How do you deal with all this? Just tell Vegas when you begin that the pixels should be tall or fat. How? Go to File/Properties, and choose the appropriate template at the top. Note that there are many different possibilities.

Finally, if you are shooting your FX1 in HDV mode and bringing HDV images over to Vegas, there are still other pixel aspect ratios. But don't worry about the actual pixel aspect ratios; just pick the format you shot in and Vegas will automatically put in the appropriate pixel aspect ratio.